Various kinds of image display devices including a liquid crystal display device have so far been used widely. A controller circuit for controlling the image display device also has been widely used. Types of images that can be displayed on the image display device and types of protocols for transmitting a signal to the image display device has increased along with development of computer technology and communication technology. The image display device is required to display various kinds of images, for example, television images and a monitor image of a computer, image data taken by a digital camera and recorded in a recording medium, and the like. As a protocol for a wireless LAN (local area network), various types of protocols such as IEEE (Institute of Electrical and Electronic Engineers) 802.11a, 802.11b, 802.11g, 802.11e, Bluetooth (Registered Trademark) and the like are used.
In a patent document 1 (Tokukai 2001-223760 published on Aug. 17, 2001; and corresponding EP 1,160,673), a configuration, wherein a wireless communication device for processing a communication protocol processes these communication protocols by a CPU (Central Processing Unit), is disclosed. In a patent document 2 (U.S. Pat. No. 6,025,840; International Publication published on Apr. 17, 1997; and corresponding Japanese PCT Laid-Open Publication 510068/1998 (Tokuhyohei No. 10-510068) published on Sep. 29, 1998), a configuration that plural display sub-systems are provided in a display controller system and each display sub-system controls reproduction of an image in corresponding area on a display screen of a display device is disclosed.
However, when the conventional configuration is applied to an image display device displaying plural types of images or images transmitted by plural types of protocols, a following problem occurs. Namely, when a CPU is caused to carry out processing of communication protocols or image display as in a manner described in the patent document 1, the CPU carries out the processing by repeating the process. Because of this, the CPU whose processing speed is relatively high becomes necessary, and circuit scale, power consumption, size and weight of the device tend to increase.
In a configuration in which a circuit for each kind of communication protocols and images is provided separately as described in the patent document 2, circuit scale, power consumption, size and weight of the display device tend to increase as the kinds of communication protocols and images increase.